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New Model from the Lamont-Doherty Earth Observatory of Columbia University
An imminent transition to a more arid climate in southwestern North America.
Projections of anthropogenic climate change conducted by nineteen different climate modeling groups around the world, using different climate models, show widespread agreement that Southwestern North America - and the subtropics in general - are on a trajectory to a climate even more arid than now. According to the models, human-induced aridification becomes marked early in the current century. In the Southwest the levels of aridity seen in the 1950s multiyear drought, or the 1930s Dust Bowl, become the new climatology by mid-century: a perpetual drought. Take home lessons: - Southwestern North America and other subtropical regions are going to become increasingly arid as a consequence of rising greenhouse gases.
- The transition to a drier climate should already be underway and will become well established in the coming years to decades, akin to permanent drought conditions.
- This is a robust result in climate model projections that has its source in well represented changes in the atmospheric hydrological cycle related to both rising humidity in a warmer atmosphere and poleward shifts of atmospheric circulation features.
For more on this topic, please go to: http://www.ldeo.columbia.edu/res/div/ocp/drought/science.shtml.
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